Stem Player & Slow Downer — Support

Last updated: August 15, 2026

Thank you for using Stem Player & Slow Downer. If you run into trouble, please check the FAQ below first. If your issue isn't covered, feel free to email us.

Frequently Asked Questions

Q. How do I get songs into the app?

Two ways. 1) From a computer on the same Wi-Fi: tap the transfer button on the top screen — the app shows an address you open in your computer's browser to send a project folder. 2) From the Files app: tap the import button and pick a folder that contains your stems.

Q. What are "stems"?

Stems are a song split into separate parts — vocals, drums, bass, and so on. You can create stems from your own recordings or purchased tracks with the free Stem Separator (Windows / macOS). Multitrack bounces you already have work as well.

Q. What is the difference between "high quality" and "standard" slow playback?

If the project contains pre-rendered slow audio, the app plays it (high quality). For speeds without pre-rendered audio, it converts in real time (standard quality). A banner tells you which one you are hearing whenever the speed is not x1.0.

Q. Does changing the key also change the speed?

No. Key change (±6 semitones) and speed are independent — you can play two semitones down at 80% speed. Double-tap the key display to return to the original key (0).

Q. How do I practice the same bars over and over?

Set the start with the A button and the end with the B button to loop that section. Markers (the flag button) let you jump straight back to your practice spots.

Q. The screen doesn't rotate to portrait.

That's by design — the app is landscape-only so the waveforms get the full width of the screen.

Q. I moved to a new device. What about my purchase?

It's a one-time purchase. Just download the app again from the App Store with the same Apple Account — no extra charge.

Contact

If your issue isn't covered above, please email us with your device model, OS version, and what happened.